


Frisk In Underswap

by CuteLittleItalian6



Category: Undertale (Video Game), underswap
Genre: Alternate Universe - Underswap (Undertale), Other, Underswap Papyrus (Undertale), Underswap Sans (Undertale), undertale - Freeform
Language: English
Status: Completed
Published: 2021-03-12
Updated: 2021-03-11
Packaged: 2021-03-18 21:29:44
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 5
Words: 3,852
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29989113
Author URL: https://archiveofourown.org/users/CuteLittleItalian6/pseuds/CuteLittleItalian6
Summary: What happens when a shortcut goes wrong and Frisk ends up in another universe? Will she be safe and more importantly will she get back home?Read and find out!
Kudos: 3





	1. Beginnings and Shortcut Accidents

**Author's Note:**

> This story is based on an RP me and my friend Icey did together on Shamchat so I had to transfer it from script form to lit, I hope it isn't too terribly written.

Frisk walked through waterfall when she noticed Sans leaning against a wall near his telescope asleep, Walking up to Sans she lightly tapped his shoulder making him open a eye socket.

"Heya kiddo, what's up?" Sans said in his usual tone.

"Hey Sans could we hang out together?" Frisk asked, wanting something to cure her boredom.

"Heh sure it's time for my break anyway, Grillby's ok with you?" Sans suggested not really knowing any better ideas.

Frisk nodded and smiled happily, she didn't really mind where they went as long as it wasn't boring.

"Grab hold of my hand then kid and we can use a shortcut." Sans instructed and held out a hand to Frisk.

Frisk grabbed onto Sans's hand and waited for Sans to use his "shortcut". But when Sans did Frisk felt her hand slip from his and she started falling until she hit the ground causing her to blackout. When Frisk woke up she noticed she was laying on a snowy ground and getting up she realized she was outside the door to the ruins. Frisk started to panic a bit inside thinking she may have accidentally LOADED an old save file and ruined all of her progress, deciding to find out if her fears were real or not Frisk started walking towards Sans's sentry station hoping he would be near it.

Making it to the poorly constructed gate Frisk felt someone approach her from behind. Turning around Frisk saw a tall figure standing behind her, suddenly the figure held out its hand.


	2. Meeting Someone You Know

Fear taking over Frisk didn't shake their hand right away but instead started to speak.

"W-Who are you?" Frisk stuttered to ask the figure.

"Don't you know how to greet a new pal?" The figure said.

Frisk sighed and shook the figure's hand.

As Frisk grabbed its hand a joy buzzer went off giving her hand a small harmless shock making her jump a bit.

"Nyeh heh, joy buzzer always funny. The names Papyrus." The figure said and it was as if the area was suddenly lit up and Frisk could now clearly see a skeleton that resembled Papyrus but wearing clothing more fitting of Sans's style.

Frisk looked at him with a confused face."You can't be Papyrus, the Papyrus I know hates jokes and pranks and is louder than you..."

"Nyeh? Me? Hate jokes and be loud? You must be thinking of my brother, Sans. Have you already met him..?" Papyrus questioned.

"Sans? I'm so confused..." Frisk said wondering if she hit her head to hard or something and she was imagining this.

"You aren't from here are you? From this timeline I mean." Papyrus says starting to put the pieces together and figure out what was going on.

"I don't think so." Frisk said.

Papyrus let out a sigh. "I'll cut the comedy then. Seems the roles are reversed in your timeline. Who lives in the ruins? A man?"

Frisk shook her head. "No a lady named Toriel lives in the ruins where I come from."

"Toriel is the queen here. A man lives in the ruins. I go there and we tell jokes from the door."

"Toriel is the queen in my timeline but she ran away after the deaths of her children and after Asgore had made the law that all humans who fell were to be brought to him and killed for their souls..." Frisk explained, frowning a bit from the memories flashing through her mind.

"So Asgore must... hm.." Papyrus nodded understandingly. "And what about the skeletons? You said it's different?"

"Sans is lazy, loves jokes and puns, going to Grillby's, and will do whatever it takes to protect his brother. Then my Papyrus hates puns and jokes, loves puzzles and spaghetti, and he dreams of being in the Royal Guard. Both of them are two of my best friends." Frisk explained more and smiled at the memories she and the brothers shared.

"Heh, I like your Sans, sounds like me. Your Papyrus sounds like my Sans, but he likes tacos. Hmm... Okay who is the royal army... guard... captain?" Papyrus said and continued his questions.

"That would be Undyne." Frisk answered.

"Alphys is the captain in my timeline. Undyne is the royal scientist. Ohh man this is weird." Papyrus said and was finding all the backwards personalities very weird and confusing.

"Can I ask you some questions?" Frisk asked.

"Go ahead kid." Papyrus answered.

"Do you have a flower named Flowey here?" Frisk questioned, wondering how her Flowey was doing.

"A whole village of them. Well one is named Frank, but yeah. It's in Waterfall don't fall for the flower flakes, they're just pieces of white paper." Papyrus explained.

"That sounds like Temmie village in my timeline." Frisk said and giggled a bit at the thought of Flowey with Temmie's personality.

"Temmie... ahh.. So Flowey for you is evil?" Papyrus questioned.

"Well he tries to be but I know he's not really evil." Frisk answered.

"Ah I see.. sort of. Anything else kid?"

"What's you human's name?" Frisk asked wanting to know if there was another her here.

"Chara. What's your name?" Papyrus answered then asked his own question.

"My name is Frisk." Frisk answered finding the thought of herself and Chara switching places weird.

"Different versions of my timeline a human named Frisk kills us all." Papyrus says with his lazy grin still present, but somehow it still felt threatening.

"Oh I know that timeline... the Chara in my timeline is evil at the end of that timeline and it's all my fault..." Frisk started to tear up at the bad memories.

"So you're a Pacifist?" Papyrus questioned.

Frisk wiped her tears and nodded.

"...Shoot kid, don't cry." Papyrus patted Frisk's shoulder. "I'm glad you are, I really don't like giving kiddos bad times."

Frisk impulsively hugs Papyrus. "I don't want a bad time again..."

Papyrus freezes for a moment before patting her back. "I don't either kiddo. Now we have a few options, we can work this out and try to get you back to your timeline or ya can stay here." Papyrus suggested.

"I need to get back before Sans and Toriel have a panic attack..." Frisk said knowing that they were probably worried sick over her.

Papyrus nodded. "Course, do you have any idea how ya got here?" He asked.

"Me and Sans were taking a shortcut to Grillby's and I accidentally let go of his hand and ended up here..." Frisk explained.

"If he's anything like me he... oh no. He's probably trying to use the machine." Papyrus said a bit of concern in his tone.

"You mean the one in the lab behind the house?" Frisk asked as if it were nothing.

"You know about that?!" Papyrus said in shock that Frisk knew about the lab.

"I found the key." Frisk said.

"Does buttfacemcfartsalot ring a bell by any chance?" Papyrus questioned.

Frisk giggled then answered. "Silly code words."

"Nyeh heh! He used the same one I do! Aw man, I'd love to meet your Sans he sounds Sansational heh." Papyrus laughed.

"He is great, you two would get along." Frisk said and smiled at the thought of the two meeting.

"Maybe I can meet him if I can get that machine working." Papyrus held out a hand to Frisk. "Don't let go this time kid." Papyrus warned.

Frisk holds his hand tight. "I won't I promise, who knows where I'd end up if I did." Frisk joked but tightened her grip just encase.

Papyrus nodded then time and space seems to bend and shift around them, leaving them just in front of the skeleton's house. "Alright let-" Papyrus was cut off by a familiar but different voice.


	3. Meeting His Brother

"MWEH HEH HEH! PAPYRUS!" Yelled the voice and Frisk could clearly see a skeleton who looked like Sans but with Papyrus's battle body and a different color scheme.

Papyrus stayed silent while Frisk jumped at the loud voice and hid behind him out of sudden shyness.

"PAP! I JU... A HUMAN! A DIFFERENT HUMAN!!! GOOD JOB PAPYRUS!" The look alike yelled.

"And this would be my Sans." Papyrus pointed out.

Frisk waved a bit at the strange Sans. "H-Hi I'm Frisk..."

"NICE TO MEET YOU! I AM THE MAGNIFICENT SANS! FUTURE MEMBER OF THE ROYAL GUARD!" The strange Sans introduced himself.

"He really is like my Pap..." Frisk commented to Papyrus.

"Mhmm, Sans we have something to do.." Papyrus started to say but was cut off by Sans again.

"LIKE WHAT?" Stars started to form in Sans's eyes. "IF IT'S MUFFET'S, I CAN MAKE BETTER FOOD! MY TACOS ARE THE BEST!"

"Muffet's? What's that?" Frisk asked.

"WHERE HE ALWAYS DOES TO EAT AND HANG OUT. IT'S JUST A BIT BEFORE OUR HOUSE!" Sans explained.

"Oh it's your timeline's Grillby's." Frisk figured out.

"Sans, uh... moke us your best tacos. I gotta show her something, ok?" Papyrus said before grabbing ahold of Frisk's hand.

"FINALLY YOU TAKE INTEREST IN MY COOKING! I'LL MAKE THE BEST TACOS I'VE EVER MADE!" Sans yelled before running into the house.

"Don't rush. Anyway..." Papyrus lead Frisk around to the back of the house before pulling out a key and unlocked the door to his lab then walked inside.

Frisk look around and noticed that it looked the same as the one in her timeline.

Papyrus walked over and and pulled the sheet off the old machine.

Frisk walks over to look at the papers and picture on the desk. "I should really ask my Sans about the stuff..." Frisk said more to herself than Papyrus.

"I think it's best he does. Might be different since it's a different timeline..." Papyrus agreed.

"It probably will be but I have questions he needs to answer." Frisk looked at the writing's on the blueprints that seemed to go to the machine.

"If I can help just lemmie know." Papyrus offered while using his magic to bring different tools over to him.

Frisk watches him work and hums a song to herself.

As Papyrus worked he let out a groan of frustration. "I doubt even Undyne could figure this out, jeeze."

Frisk walked over to look at the machine. "Maybe you should think of it like a hard puzzle and maybe you will see the answer?" Frisk suggested.

"Puzzles? Might as well get Sans in here then." Papyrus chuckled before furrowing his brow bone.

"Maybe Sans could help?" Frisk questioned.

"I can't tell him 'bout this stuff, he needs to be happy." Papyrus said.

"What's so depressing about this stuff?" Frisk asked.

"He might remember Gaster, I can't have that happen. It's bad enough I have to live with those memories." Papyrus explains.

"You have a Gaster her?" Frisk was happy to see a few similarities between this timeline and her own.

"Yeah we did, he pops up every so often. But I personally couldn't care less for him." Papyrus said bitterly.

"No one but me has seen Gaster in my timeline." Frisk pointed out.

"...You saw him?" Papyrus asked.

"He was behind a door in Waterfall I think." Frisk answered.

"I'll check it out later, you're my priority now. The human who was supposed to be in my timeline might have gone to yours to make up for you leaving, knowing how Gaster and his stupid timelines work." Papyrus said obviously not caring for and had a bad relationship with his Gaster.

"Wait you said your human was Chara right?" Frisk asked just realizing something important.

"Yeah, she's good in this timeline... usually. She goes by your name when she isn't." Papyrus answered while attempting to get the machine working.

"We need to hurry up if she's in my timeline!" Frisk yelled now obviously panicked.

"Chara is good in my timeline, why would she be bad there?" Papyrus asked now very confused to why Frisk was suddenly alarmed.

"You don't understand if my Sans sees her he will kill her!" Frisk yelled again.

"There isn't a way he would hear her out? I always wait until she kills..." Papyrus was skeptical that Frisk's Sans would kill with no motive.

"He might, but if it's Chara he might not because of what my timeline Chara did!" Frisk wanted to believe Sans wouldn't hurt his Chara but she was too scared to believe it.

"Shit, you might be right. I'm working as fast as I can kiddo, I don't have determination like yo..." Papyrus paused and looked Frisk over. "Determination..."

Frisk tilted her head. "What?"

Papyrus was suddenly very excited. "That must be what I'm missing! Determination, that's why I could never get it to work! Weird request... but can I use your soul real quick?" Papyrus asked.

Frisk paused for a moment before nodding.

Using his magic Papyrus pulled Frisk's soul carefully to the machine, which let off an electric buzz. "I knew it..."

Frisk flinched a bit from the weird feeling. "What is it?" She asked.

"The machine needs soul power, determination. This might sting a bit." Papyrus explained and warned before bringing Frisk's soul closer, focusing as he tried to power up the machine. Miraculously he got it running, but at the cost of a good majority of her HP.

"..." Papyrus got out a hotdog from his jacket and handed it to Frisk. "Sorry kid." He apologized.

Frisk smiles weakly and accepts the hotdog, eating it slowly. "It's ok I've been through worse." She says between bites.

"Thanks for the soul power though. I'll make sure to let your Sans know how to make this work." Papyrus thanked frisk then messed with a few wires outside the machine before leaning in and pressing buttons inside.

"I hope it doesn't kill me to get his running to..." Frisk jokes but was actually concerned about that possibility.

"I'll make sure that it won't." Papyrus winks then climbs into the machine. "Come on, I need you for this." He says from inside.

Frisk nodded and climbed inside herself.

Papyrus carefully takes ahold of Frisk's soul again, using it to bring up calculations on a monitor. "I can bring us back to your last save, I think." He said sounding a bit unsure.

"My last save was in Snowdin I think, that might be why I landed in your Snowdin." Frisk pointed out, wondering if the machine would actually get her home.

Papyrus nodded and hesitated for a moment. "Here goes nothin." He says before pressing a big red button, time and space shifting around the machine.


	4. Landing and Reuniting

They land safely with half power left in Snowdin forest just outside of town.

"Whoa it... worked." Papyrus said in amazement.

"Are you sure it's the right place?" Frisk asked scared they may have ended up in the same place or worse.

"Seems like it. C'mon, let's see." Papyrus says while getting out, protectively keeping Frisk close to him.

Frisk followed him out and stayed close to him, gripping onto his hoodie for extra security.

As they walked Papyrus was shocked at how opposite everything was.

"It sure as hell isn't my timeline..." Papyrus commented.

"I hope this is the right place, I don't want to end up some place scary..." Frisk said, her fears still present in her mind.

"Don't worry kid I got ya." Papyrus said and wrapped an around her.

They continued walking and soon ended up in front of the skeleton house.

"Where might your Sans be?" Papyrus asked Frisk.

"He could be here, one of his sentry/hotdog stands, or at Grillby's" Frisk answered.

"Where do you think is most likely?" Papyrus questioned further.

Frisk thought for a moment before finally answering. "Grillby's."

Papyrus nodded and began walking to where, in his timeline, he knew Muffet's was.

Upon entering the monsters greeted Papyrus thinking he was the one from this timeline.

"Hey Paps! Hey Papyrus! Cool new clothes!" Where some of the things the two heard from some of the monsters.

Frisk let out a small giggle finding the mistaken identity amusing and looked around for Sans.

Sans was seated in his usual spot at the bar, drinking from a bottle of ketchup.

Frisk pulled Papyrus over to Sans excitedly.

Sans looked over at the two, cocking a brow bone. "Papyrus? What are you doin here?... Who's the kid?" He asked very confused.

Frisk frowned when it seemed that Sans didn't remember her.

"I need to speak with ya outside." Papyrus said.

Sans nodded and got off the bar stool.

Once all three were outside Papyrus explained the situation.

Sans looked between Frisk and Papyrus then suddenly his memory came back.

"You scared me kiddo, don't let go next time, got it?" Sans said and was using a slight stern tone.

Frisk hugged Sans tightly, happy he remembered her. "I'm sorry Sans I didn't mean to..." She apologized.

Sans hugged Frisk back. "Don't worry 'bout it kiddo but uh... I saw the other human go off with Pap... should I be worried?" He questioned, worrying about his brother's safety.

"No that's just his human and she's nice." Frisk answered.

"She's usually nice, her name is Chara." Papyrus added.

"I don't trust the name, but I don't think she's killed anyone here. Let's go get her then." Sans said and started walking in the direction his brother and the human went.

Frisk held onto Sans's hand as they walked. "We'd better hurry before our Papyrus drives her crazy with puzzles." Frisk joked and laughed a bit.

"Nyeh heh, if he's anything like my Sans it won't take long." Papyrus says jokingly.

"I have a good amount of questions..." Sans says and leads them to Snowdin forest.

"He and your Sans are exactly alike except for looks." Frisk said to Papyrus and stayed close to Sans, happy to be back with her friend.

Papyrus lit up a cigarette as Sans chuckled.

"Sounds interesting, might have to make a trip over if this Pap'll show me how." Sans says, his curiosity peaked.

"I will, but let's make sure my human isn't causing trouble." Papyrus said, planning to show him later or Frisk would explain it.

Frisk frowned at Papyrus smoking. "Smoking is bad for you..." She scolded and made sure not to breath in the smoke.

"Okay Sans.. er my Sans?" Papyrus says sarcastically and sorta confused.

Sans chuckles."Heh I'll stick to my ketchup." He commented.

It wasn't long before "Nyeh heh heh" could be heard through the forest.

"I hear Papy!" Frisk yelled and took off towards the sound.

"That's what I sound like here?" Papyrus questioned at hearing his counterpart's voice.

"Heh, yep." Sans answered.

Soon they all reached when Frisk and Sans's, Papyrus is.


	5. Goodbyes and Endings

Papyrus looked at them. "Human? Another human! Two Humans! Undyne will be double proud of me!" He yelled in excitement.

"Aww, he doesn't remember me..." Frisk said in a disappointed tone.

"Of course I do! Your sweater is different! I thought you changed it earlier!" Papyrus yelled again.

"Chara?" US!Papyrus questioned.

"Oh! Another skeleton, Sans who is this?" Papyrus asked, looking at his counterpart.

"Papyrus that is you from another universe and the other human you were with is from his universe also." Frisk explained.

"Wowie! You dress a lot like Sans though! Do you also like puzzles and spaghetti?!" Papyrus asked, his excitement increasing.

"...That's more my brother's thing, he likes tacos instead." US!Papyrus answered.

"How... disappointing, but I'm sure we can still be great friends!" Papyrus smiled, filled with optimism.

"Pap, he and his human gotta go home to their own world." Sans explained.

"Where is the other human?" Frisk asked.

"She was right here... I was showing her my puzzle..." Papyrus answered wondering where the human went to.

"Chara? Come on, I'm too lazy for hide and seek. I'm sure our Sans will be up for it." US!Papyrus called out while looking for his human.

"Sans? Not being lazy? Impossible!" Papyrus yelled shocked from hearing something he thought could never be true.

Frisk giggles a bit and helps look for the human.

A human with a similar appearance to Frisk pokes their head out from behind a tree.

Frisk noticed her and gives her a non-threatening smile. "No need to be scared we won't hurt you..." Frisk says reassuringly.

"H-Hi..." The human said and stepped out from behind the tree, looking over at US!Papyrus. "I'm supposed to be with you right?" She asked.

"Yup, I mean I'm not gonna force you to leave, too lazy and what not. But you are supposed to be in my timeline, good or bad." US!Papyrus answered.

Frisk held her hand out to the other human. "Hi I'm Frisk, it's nice to meet another nice human." She introduced herself politely.

The human shook Frisk's hand. "I'm Chara. My name isn't liked around here... Toriel got upset when I said it..." Chara explained and looked down.

"Oh boy." Sans commented.

"Your name isn't very liked because your version here is very depressing to a lot of people." Frisk stated.

"... I wish I could say sorry for upsetting Toriel." Chara said sadly and with a guilty tone.

"I'll tell her kiddo, but for now maybe we should all get back to our own timelines..." Sans volunteered and expressed his concern about being out of their timeline for too long.

"Yeah, besides my Sans is making tacos for two and we can't let that go to waste." US!Papyrus said with a small chuckle.

"Heh." Sans laughed.

"Maybe we could visit you again or you could visit here someday?" Frisk suggested.

Sans and US!Pap shared a look, both nodding.

"It might not be best to mess with the timelines more." US!Pap said with genuine concern.

"Don't want anyone to turn out like Gaster." Sans added.

"I'm very confused..." Papyrus said.

"Oh that reminds me, Sans we need to talk about what's behind your house!" Frisk said just remembering the lab.

"There's something behind our house?!" Papyrus asked, even more confused.

"Later kid." Sans said, not wanting to talk about that in front of his brother.

"Can ya tell him what we learned about how we got here, kiddo?" US!Papyrus asked Frisk.

Frisk nods and smiles brightly. "Hey Pap I think your puzzle in the next area needs recalibrating!" Frisk said trying to give him something to do.

"Oh! Really?! Thank you human, let's go check!" Papyrus yelled and ran off to go check his puzzle.

"Heh, thanks for bringing her back here. I almost cracked my skull I was so worried." Sans thanked US! Pap.

"No problem, thanks for looking after Chara." US!Papyrus thanked Sans back.

Chara gripped onto US!Pap's sleeve. "I'm ready to go..." She said softly.

Frisk hugged Sans. "I'm glad to know you care about me that much Sans." Frisk said with a smile.

Sans shrugs and pats Frisk's head. "Course kiddo, that and I don't want Tori killing me. Who'd tell her jokes?" Sans said and laughed nervously.

"Nyeh heh, well it was nice meeting ya kid. Come on Chara." US! Pap said and walked with Chara back to the machine with Frisk and Sans waving behind them.


End file.
